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Bilge vents

Posted: Wed Mar 31, 2010 5:46 pm
by larryeddington
My f28 did not come with a rear one but you can bet before I sail her I am going to get one after reading this story.

Posted: Thu Apr 01, 2010 9:39 pm
by turtlem1969
my f25 has 4 vents, two forward ones face aft and have the blowers hooked to them, the two aft face forward, I have two rear bilge pumps, since mine has a tunnel one on each side of the tunnel, plus a forward bilge pump.

Posted: Sat Apr 03, 2010 9:03 am
by guglielmo6160
Image
'One dog goes one way and the udda dog goes the udda way, and this guy's sayin, whatdaya want from me"

(sorry)

Posted: Sat Apr 03, 2010 9:36 am
by prowlersfish
There are two ways to install the vents the right way and the wrong way .

The rear facing vents ( exhaust ) will be hooked up to hoses that go to the lower part of the bilge to remove gas fumes . the inlets facing forward often do not have hoses ( not always )

The reason the rear facing vents in many cases are the front vents is due to engine placement and the need to remove fumes from that area

bilge vents

Posted: Sun Apr 04, 2010 5:57 pm
by larryeddington
As I said earlier I will install an aft bilge pump, as the f28 does not have one. I was reading in chapmans a good idea for very sever emergency. Chapman's suggest that putting a T with a valve infront of raw cooling water sea strainer and that tee hooked to a hose to the bilge. In a serious emergency either engines raw water pumb could then be used for a bilge pump, of course one would want to watch the engine temp incase it was too efficient. As long as the engines would run they could be used to augment other bilge evacuaion methods. :)

Posted: Wed Apr 07, 2010 8:01 am
by rossjo
Paul is right (surprise) ... and I agree totally with Larry - crash pumps are a great idea - I haven't added them yet, but could cut a hose if need be to suck fromt he bilge (better than sinking).

1970's F32s and F36s came with the forward vent facing back and the rear vents facing forward. My vents are the opposite of this, and work well.

Here are some original ads from 1974, 1975 & 1977 for reference:

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1974 Trojan Ad

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1975 Trojan Brochure (I can hear Tom Jones singing)

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1977 Trojan Ad

Posted: Wed Apr 07, 2010 9:31 pm
by RWS
if you can, plumb the crash pumps before your seastrainer OR put a screen over the emergency intake in the engine room to keep debris from wiping out your impeller.

I have crash pumps set up AND a fresh water flush for all heat exchangers.

RWS

Posted: Wed Apr 07, 2010 9:37 pm
by RWS
As far as the ventilation is concerned, at cruise speed, the engines are ingesting a tremendous CFM volume of air and blowing it out the exhaust.

Wrong facing vents can cause air starvation - as in a VACUUM in th eengine room.

RWS

Posted: Thu Apr 08, 2010 9:32 am
by rossjo
The front vents (on my F32) feed closed air boxes that the blowers/hose connect to.

The rear vents are thus the only source of air for the engines. The intakes on my Cummins turbos are on the back of the engine, with large filters. I think the prior owner faced them back to reduce ingestion of salt water spray, but its hard to say.

I doubt the direction fo the vents has much "ram" affect (forward) or air starvation (rearward), since most of our boats dont exceed 30 knots anyway.

I think the direction has more to do with avoiding spray. I get a bit of mist in the air behind the boat at 6-12 knots. The air coming down the side of the boat tends to blow this mist backwards and keep it from sucking in these rear vents.

Offshore, facing these aft engine-feeding vents backwards keeps heavy spray from entering directly into the vents.

This is an interesting discussion, and I will confirm my theory Saturday.

Posted: Mon Apr 12, 2010 9:26 pm
by guglielmo6160
does anyone know where I can get a shirt like the guy in that picture?

Posted: Mon Apr 12, 2010 11:37 pm
by TADTOOMUCH
Trojan, built for tough customers like your wife.
Are they selling boats or condoms with that advertisement slogan?

Posted: Wed Apr 14, 2010 6:53 am
by rossjo
guglielmo6160 wrote:does anyone know where I can get a shirt like the guy in that picture?
Bill,

I think I have one in the back of my closet.
:D
I'm sure my wife wouldn't be upset if I sent it to you!
;-)
Do you need the gold chain too?
:lol:

Image

Posted: Wed Apr 14, 2010 8:01 pm
by foofer b
1975 Trojan Brochure (I can hear Tom Jones singing)[/size]

"It's not unusual to be loved by anyone..."

Posted: Wed Apr 14, 2010 9:26 pm
by rossjo
Thats EXACTLY what went through my head when I saw this picture. I think the "chick's" skirt on the top deck is made from the same drapes!

:D

Posted: Thu Apr 15, 2010 6:35 pm
by guglielmo6160
what was going on in our heads in the late 70's and 80's LOL